Beginner traders can make several mistakes while trading. Some common mistakes include not researching the markets properly, trading without a plan, over-reliance on software, failing to cut losses, and overexposing a position. Another common mistake is starting to trade without creating a trading plan. It is also important to keep a personal track record of trading mistakes to learn from them. Beginner traders should do their homework before investing in any altcoin. It is essential to avoid these common trading mistakes to become a successful trader.